With the permission of DonH and credit to waterwolve, i present you a great article on Salt FAQ

Salt FAQ

My views towards the use of salt are simple... Don't use it unless it?s needed. Salt is not a miracle cure and it has its limitations. It's up to you to monitor the progress of your sick fish and decide if more potent meds are needed to assist your fish in recovery.

The reasons why I like salt:
1) It will not affect your biological filtration (does not kill nitrifiers if not grossly overdosed)
2) Carbon does not take it out of the system
3) A UV sterilizer will not render it useless
4) It's cost effective and will not cost a fortune to treat large tanks/ponds
5) It is one of the least invasive methods of treatment and usually will not push very sick fishes over the edge like other meds
6) Can be used on most fish species that are sensitive to other meds (Note: livebearers and cichlids will generally tolerate much higher levels of salt than many freshwater fishes such as characins (tetras), loaches, and catfishes)
7) It is not carcinogenic and is not harmful if ingested or upon direct skin contact
8) Has a relatively wide margin for error in dosing
9) Widely available (Home Depot or grocery stores)
10) Versatile... can be used as a long term bath (2 weeks) or a short term dip

What salt will do:
1) Relieves nitrite poisoning (Brown Blood disease) by displacing nitrite ions away from gills membrane.

QUOTE
A little math and chemistry just for the heck of it? Salt treats nitrite poisoning when the chloride ion (Cl-) concentration is about 30 times that of the nitrite ion (NO2-) concentration in the water. This displaces the nitrite ion across the gill membranes and prevents it from entering into the bloodstream. Since nitrites are toxic at about 0.1 mg/L, this means the chloride ion concentration would have to be at least 3.0 mg/L.

If you look at the atomic weight of sodium and chloride, you'll find that the chloride ion (Cl-) is 60.66% of NaCl (chloride ion/sodium+chloride = 35.453/58.44=0.6066). This translates to about 5.0 mg/L of chloride needed (3.0 mg/l divided by .6066). There are 3.78 litres in 1 US gallon which basically means you will need 18.9 mg/gallon of salt (5 mg/l * 3.78l/US gallon) to relieve nitrite poisoning. Since a teaspoon of table salt is about 5.5 grams (5,500 mg), a TEASPOON of table salt would be enough to protect fish in approximately 300 gallons of water! In other words, a little goes a LONG way...

Probably a little more than you would want to know but that's how it's calculated.

2) Eradicates a large number of external parasites including ich, chilodonella, costia, trichodina, oodinium (velvet).
3) Combats bacterial, fungal infections and ammonia burn.
4) Kills all salt sensitive plants
5) Recharges ion exchange resins (ammo-chips, water softener "pillows")
6) Can be used to disinfect a used, empty tank by apply it as a "paste" (although there are better alternatives
7) Ease osmoregulatory stress... This problem is not a concern because we are dealing with FRESHWATER fishes. Exceptions are when fish have open ulcers or are under stress resulting in kidney functions being impaired.

Salt is NOT effective in or will NOT:
1) Will NOT treat for fish lice (argulus), anchorworms (lernea), skin and gill flukes, internal parasites.
2) Will NOT replace electrolytes and trace minerals (unless you are using a marine salt mix which also has buffers that will increase your pH). We are talking about pure salt (NaCl) so the only elements added to water are basically sodium (Na+) and chloride (Cl-).
3) Will NOT treat viral infections (like lymphocystis) or tumors


QUOTE
Myth: Iodine from table salt will NOT kill your fish. The low levels present in table salt will not reach toxic level, even at treatment levels. Your fish will die of osmotic shock or high salinity before iodine becomes toxic. I have yet to hear of a single case where fish were killed from the use of iodized table salt. If you are still not convinced, cheaper alternatives to aquarium salt are non-iodized table salt, kosher salt, water softener salt (my local Home Depot sells 40 lb. bags for under $5 that are 99.8% pure NaCl).


How to administer:

The commonly accepted dosage for salt is at 0.3% (which is a TOTAL of 2.5 lbs/100 gallons or 3 tsp/US gallon). The amount of salt added should be done in 3 equal increments over 3 days and left in the system for 2 weeks (that's 1 tsp per gallon per day for 3 days), in which time, the salt should be taken out through water changes. In the event of a water change during treatment, replace the amount of salt lost in proportion to the volume of water changed. Example: If 10 gallons of water is replenished, than an additional 30 tsp of salt should be added. I have ALWAYS dosed my tanks at 0.3% (3 tsp/gallon) during treatment. Only exception to this rule is for nitrite poisoning where a teaspoon of salt will treat over 300 gallons of water. Many believe that the constant use of salt in low dosages as a prophylactic is the reason why we have problems with salt resistant parasites. As a result, to treat some parasitic infestations, we need to double the dosage to 0.6% to see any significant improvement. ALWAYS pre-dissolve salt before introducing to your tank! Measure out the desired amount of salt, add water to a bucket or large cup (I use a 44 oz plastic "Big Gulp" cup) and stir like crazy until the salt dissolves. Slowly pour the salt solution into the tank making sure you are not pouring it directly on top of a fish. I prefer to pour the solution in the path of a powerhead or filter output to help quickly distribute it throughout the tank. A "blast" of concentrated salt solution may cause severe burns to your fish. Therefore, NEVER add salt directly to your tank.

For salt dips, a 1% solution (9 tsp/gallon) can be used for around 10-15 minutes and then the fish is returned to clean aquarium water. For extreme cases (and as a last resort), a strong 3% salt solution can be used. The fish must be constantly monitored and is basically kept in the bath until they roll over and is transferred IMMEDIATELY back to the aquarium. Fish will try to adjust to the changing salinity and the longer you wait, the more adjustments the fish needs to make. I'm not a big fan of salt dips because they are very stressful on the fish.

One final note, as mentioned earlier, livebearers and cichlids will tolerate much higher levels of salt than many other freshwater fishes such as characins (tetras), loaches, and catfish. Many of these tropical fish come from soft, acidic rivers that are low in GH, pH, and TDS (total dissolved solids). Even though salt does not affect the general hardness and pH of water, it does drastically increase the TDS which many of the more sensitive fish are not accustomed to. So this practice is not recommended for all species.

I do not believe that salt should be constantly used in the aquarium as a general tonic. They are freshwater fish and should remain so.

Thanks Don!

Great info... have to look into that home depot salt thing.

anyone in NY seen mortons salt at home depot feel like an ass paid 7 bucks for a half gallon size of salt at petland and seen a bag for 5 bucks online

Great write up bro. Thanks.

i just buy the cooking one

Same here, I used to pay 7 bucks for half galon box. Now I've paid 5 bucks for 50 lbs. at home depot.

great idea whats the stuff from home depot called?

water softner might have it more in LI gonna check home depot

I got the Blue Bag of Mortons water softner salt about 40lb might get more just to stock up

hey guys do i have to dissolve the salt first? or its ok to throw it in the tank solid....

best to dissolve it first with tank water or you can just throw it in the wet/dry filter.

The stuff from home depot is great spyder got me some 80lbs I use it all the time cause it kills alot of things that love no salt the only bad thing is if you have snails theyre shell grows from the menurals the salt has and they thrive on it salt

this one will work?

Bingo

so much do i need to put? every WC?